Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535739
Chen Bo, Zhao Mei, Hu Changqing
The ambient noise field in shallow water is contributed to by many noise sources and it is also influenced by environment boundaries. The ambient noise field strongly depends on the properties of the seabed, so it is often used for undertaking geoacoustic inversion. Geoacoustic inversion is performed using either vertical coherence or directionality, as these are relatively stable features of noise and are largely determined by the seabed. Certain parameters of the seabed, such as the sound speed, density and attenuation are usually the focus in this field of research. However, an additional parameter, namely the thickness of the sediment, also has a significant effect on the ambient noise field. The purpose of this paper is to determine the effect of sediment thickness on the ambient noise field in shallow water. In the first step, a model is constructed, with the shallow water divided into three layers - water, sediment and elastic seabed. The vertical coherence is obtained from the ambient noise model which is based on normal mode theory. Once the model is completed, simulations are performed on two key aspects in order to determine how sediment thickness influences vertical coherence. In the first simulation, all parameters except for the sediment thickness are kept constant. The result from the first simulation shows that the coherence curve becomes increasingly flat with the increase of sediment thickness. In the second simulation, four thicknesses are chosen, 0.5m, 1m, 2m, 10m respectively. For each thickness, four vertical coherence curves for different sound speeds and attenuation are plotted in the same figure. By comparing these four figures, it is seen that the vertical coherence becomes less sensitive to the parameters in the seabed with the increase of sediment thickness. Once the sediment thickness exceeds 1m, the curve remains nearly unchanged with changes in the shear wave speed and attenuation in the seabed. However, the vertical coherence is still sensitive to the compressional wave speed. Therefore, the thickness of sediment plays an important role in geoacoustic inversion. When the sediment is deep enough, the vertical coherence can only be used to undertake inversion on compressional wave speed rather than on other parameters.
{"title":"The influence of sediment thickness on vertical coherence of ambient noise in shallow water","authors":"Chen Bo, Zhao Mei, Hu Changqing","doi":"10.1109/COA.2016.7535739","DOIUrl":"https://doi.org/10.1109/COA.2016.7535739","url":null,"abstract":"The ambient noise field in shallow water is contributed to by many noise sources and it is also influenced by environment boundaries. The ambient noise field strongly depends on the properties of the seabed, so it is often used for undertaking geoacoustic inversion. Geoacoustic inversion is performed using either vertical coherence or directionality, as these are relatively stable features of noise and are largely determined by the seabed. Certain parameters of the seabed, such as the sound speed, density and attenuation are usually the focus in this field of research. However, an additional parameter, namely the thickness of the sediment, also has a significant effect on the ambient noise field. The purpose of this paper is to determine the effect of sediment thickness on the ambient noise field in shallow water. In the first step, a model is constructed, with the shallow water divided into three layers - water, sediment and elastic seabed. The vertical coherence is obtained from the ambient noise model which is based on normal mode theory. Once the model is completed, simulations are performed on two key aspects in order to determine how sediment thickness influences vertical coherence. In the first simulation, all parameters except for the sediment thickness are kept constant. The result from the first simulation shows that the coherence curve becomes increasingly flat with the increase of sediment thickness. In the second simulation, four thicknesses are chosen, 0.5m, 1m, 2m, 10m respectively. For each thickness, four vertical coherence curves for different sound speeds and attenuation are plotted in the same figure. By comparing these four figures, it is seen that the vertical coherence becomes less sensitive to the parameters in the seabed with the increase of sediment thickness. Once the sediment thickness exceeds 1m, the curve remains nearly unchanged with changes in the shear wave speed and attenuation in the seabed. However, the vertical coherence is still sensitive to the compressional wave speed. Therefore, the thickness of sediment plays an important role in geoacoustic inversion. When the sediment is deep enough, the vertical coherence can only be used to undertake inversion on compressional wave speed rather than on other parameters.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116947890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535758
T. Le, Chen Hong-juan, Z. Hu, Zhao Tian-Ji, Li Zhi
The hydrophone calibration system in a small water tank has broad application prospects. This paper studies some theory evidence of the practicability of the hydrophone calibration system in a small water tank. Simulation of the sound field in a small water tank shows the distribution of the acoustic field there in. An experiment is conducted to compare a vector hydrophone with a standard hydrophone, and, calibrate the sensitivity of the vector hydrophone, and thence calibrate the directivity pattern. The frequency is ranged from 50Hz to 1000Hz. Finally, the paper compared the result of calibration with the theoretical sensitivity and directivity pattern.
{"title":"Research on calibrating vector hydrophones in small water tank","authors":"T. Le, Chen Hong-juan, Z. Hu, Zhao Tian-Ji, Li Zhi","doi":"10.1109/COA.2016.7535758","DOIUrl":"https://doi.org/10.1109/COA.2016.7535758","url":null,"abstract":"The hydrophone calibration system in a small water tank has broad application prospects. This paper studies some theory evidence of the practicability of the hydrophone calibration system in a small water tank. Simulation of the sound field in a small water tank shows the distribution of the acoustic field there in. An experiment is conducted to compare a vector hydrophone with a standard hydrophone, and, calibrate the sensitivity of the vector hydrophone, and thence calibrate the directivity pattern. The frequency is ranged from 50Hz to 1000Hz. Finally, the paper compared the result of calibration with the theoretical sensitivity and directivity pattern.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123882552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535738
Jia-xuan Yang, Lin He, C. Shuai
In the simulation of underwater acoustic propagation, sound speed is usually characterized by the vertical distribution of the sound speed profile (SSP), but it ignores lateral variation. This paper carried out simulation on constant SSP, negative and positive gradient profile, and real sound speed profiles (SSPs), concerning a Gulf Stream scenario, and by using Bellhop model. The characteristics of underwater acoustic propagation in the horizontal direction are discussed. The results show that the changes of sound velocity in the horizontal direction have a certain effect on underwater sound propagation. With the horizontal sound speed increasing for the steady SSPs, the number of eigenrays increase, and the transmission loss and the arrival times decrease. Conversely, the number of eigenrays decrease, and the transmission loss and the arrival times increase. With the horizontal changes of the unsteady SSPs, underwater acoustic propagation is basically followed by this law, but the transmission loss may change suddenly in some cases. It has a certain reference value for underwater acoustic modeling. Further work will be discussed and analyzed in the future.
{"title":"The simulation of underwater acoustic propagation with the horizontal changes of sound speed profiles","authors":"Jia-xuan Yang, Lin He, C. Shuai","doi":"10.1109/COA.2016.7535738","DOIUrl":"https://doi.org/10.1109/COA.2016.7535738","url":null,"abstract":"In the simulation of underwater acoustic propagation, sound speed is usually characterized by the vertical distribution of the sound speed profile (SSP), but it ignores lateral variation. This paper carried out simulation on constant SSP, negative and positive gradient profile, and real sound speed profiles (SSPs), concerning a Gulf Stream scenario, and by using Bellhop model. The characteristics of underwater acoustic propagation in the horizontal direction are discussed. The results show that the changes of sound velocity in the horizontal direction have a certain effect on underwater sound propagation. With the horizontal sound speed increasing for the steady SSPs, the number of eigenrays increase, and the transmission loss and the arrival times decrease. Conversely, the number of eigenrays decrease, and the transmission loss and the arrival times increase. With the horizontal changes of the unsteady SSPs, underwater acoustic propagation is basically followed by this law, but the transmission loss may change suddenly in some cases. It has a certain reference value for underwater acoustic modeling. Further work will be discussed and analyzed in the future.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134347143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535804
Shane Guan, J. Vignola, J. Judge, D. Turo
In this study, we analyzed continuous acoustic recordings collected from a bottom-mounted hydrophone deployed in coastal shallow waters of the U.S. Beaufort Sea during a marine seismic survey in the summer of 2012. Two quantitative methods were developed to compare the inter-pulse sound field, defined as the acoustic field between two consecutive airgun pulses, with the ambient noise level. Results show that during periods when seismic airguns were active, inter-pulse sound field could exceed ambient noise levels by as much as 9 dB. Kolmogorov-Smirnov two-sample tests between inter-pulse sound levels and ambient noise levels showed significant differences in median SPLs. Spectral analysis of inter-pulse sound fiend in one-third-octave bands in relation with known and hypothetical marine mammal hearing sensitivities indicates potential acoustic masking during a seismic survey, even for animals at relative far distances from a survey vessel. Degrees of acoustic masking are related to frequency-depended hearing sensitivities of marine mammals. For the endangered bowhead whales, which are most sensitive to low-frequency sounds, acoustic masking is expected to be most severe as most energy from seismic airgun pulses is below 500 Hz. These results underscore the need for further research on reverberant field of marine seismic surveys and its potential impacts on marine animals.
{"title":"Characterization of marine seismic survey inter-pulse sound field in an Arctic shallow-water environment","authors":"Shane Guan, J. Vignola, J. Judge, D. Turo","doi":"10.1109/COA.2016.7535804","DOIUrl":"https://doi.org/10.1109/COA.2016.7535804","url":null,"abstract":"In this study, we analyzed continuous acoustic recordings collected from a bottom-mounted hydrophone deployed in coastal shallow waters of the U.S. Beaufort Sea during a marine seismic survey in the summer of 2012. Two quantitative methods were developed to compare the inter-pulse sound field, defined as the acoustic field between two consecutive airgun pulses, with the ambient noise level. Results show that during periods when seismic airguns were active, inter-pulse sound field could exceed ambient noise levels by as much as 9 dB. Kolmogorov-Smirnov two-sample tests between inter-pulse sound levels and ambient noise levels showed significant differences in median SPLs. Spectral analysis of inter-pulse sound fiend in one-third-octave bands in relation with known and hypothetical marine mammal hearing sensitivities indicates potential acoustic masking during a seismic survey, even for animals at relative far distances from a survey vessel. Degrees of acoustic masking are related to frequency-depended hearing sensitivities of marine mammals. For the endangered bowhead whales, which are most sensitive to low-frequency sounds, acoustic masking is expected to be most severe as most energy from seismic airgun pulses is below 500 Hz. These results underscore the need for further research on reverberant field of marine seismic surveys and its potential impacts on marine animals.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134358555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535620
Jun Zhang, Xiao Zhou, Ting Li, Geng-xin Ning, Yizhi Feng
Cooperative communication can realize spatial diversity advantages in a distributed manner and has been successfully applied to underwater acoustic communication recently. However, the conventional synchronous two-stage cooperative modes are less efficient in underwater environments due to the long synchronization time and intermittent data transmission. In this paper, an asynchronous full-rate underwater cooperative communication scheme is proposed to reduce the cooperative delay and improve the transmission rate. In the proposed scheme, the source node transmits data packets successively and two relays retransmit the even and odd frames respectively without synchronizing with other nodes. The experimental results show that the proposed scheme outperforms the direct transmission and several conventional cooperative transmission schemes in underwater environments.
{"title":"Asynchronous full rate cooperative transmission for underwater acoustic communication","authors":"Jun Zhang, Xiao Zhou, Ting Li, Geng-xin Ning, Yizhi Feng","doi":"10.1109/COA.2016.7535620","DOIUrl":"https://doi.org/10.1109/COA.2016.7535620","url":null,"abstract":"Cooperative communication can realize spatial diversity advantages in a distributed manner and has been successfully applied to underwater acoustic communication recently. However, the conventional synchronous two-stage cooperative modes are less efficient in underwater environments due to the long synchronization time and intermittent data transmission. In this paper, an asynchronous full-rate underwater cooperative communication scheme is proposed to reduce the cooperative delay and improve the transmission rate. In the proposed scheme, the source node transmits data packets successively and two relays retransmit the even and odd frames respectively without synchronizing with other nodes. The experimental results show that the proposed scheme outperforms the direct transmission and several conventional cooperative transmission schemes in underwater environments.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134475928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535802
Ruiqin Zhao, Haodi Mei, Xiaohong Shen, Wei Fang, Haiyan Wang
In this paper, an underwater acoustic network system is presented and produced, which consists of five underwater acoustic node devices with a networking capability. The underwater acoustic network system adopts the high speed hardware architecture of DSP plus FPGA, and utilizes a Time Division Multiple Access (TDMA) mechanism when networking. The system could not only supply quick and reliable underwater acoustic communication at a physical layer, but also complete stable networking at higher layer based on TDMA. At the physical layer, a one-hop underwater acoustic communication rate of 500 bit/s at the range of 2000m is achieved. And the system could complete node localization of the network through a ranging method between neighbouring nodes. At the upper layer, a TDMA medium access control mechanism is produced in the presented underwater acoustic network system. Finally an anechoic pool experiment has proved the stability and validity of the proposed underwater acoustic network system.
{"title":"Underwater acoustic network node design and anechoic pool network experimentation with five nodes","authors":"Ruiqin Zhao, Haodi Mei, Xiaohong Shen, Wei Fang, Haiyan Wang","doi":"10.1109/COA.2016.7535802","DOIUrl":"https://doi.org/10.1109/COA.2016.7535802","url":null,"abstract":"In this paper, an underwater acoustic network system is presented and produced, which consists of five underwater acoustic node devices with a networking capability. The underwater acoustic network system adopts the high speed hardware architecture of DSP plus FPGA, and utilizes a Time Division Multiple Access (TDMA) mechanism when networking. The system could not only supply quick and reliable underwater acoustic communication at a physical layer, but also complete stable networking at higher layer based on TDMA. At the physical layer, a one-hop underwater acoustic communication rate of 500 bit/s at the range of 2000m is achieved. And the system could complete node localization of the network through a ranging method between neighbouring nodes. At the upper layer, a TDMA medium access control mechanism is produced in the presented underwater acoustic network system. Finally an anechoic pool experiment has proved the stability and validity of the proposed underwater acoustic network system.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115327315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535663
Jinshi Liu, S. Chao
For solving the prediction problem of sound radiation from structures, both the structural and acoustical regions have to be researched. Fluid-structure interaction incorporates the mutual influence of acoustical medium and structure. This interaction occurs at the coupling interface between the two adjacent domains. In case of thin structures and dense fluids, a strong coupling scheme between the two problems is essential, since the feedback of the acoustic pressure onto the structure is not negligible. In this paper, the structural part is modeled with the finite element (FE) method. An interface to the commercial finite element package ANSYS is set up to import the structural matrices of stiffness and mess. The exterior acoustic problem is efficiently modeled with the boundary element method, and the CHIEF method with internal nodes generated randomly is adopted to avoid non-uniqueness of solution. Classical BEM formulations suffer from fully populated matrices, leading to a restriction in both memory consumption and computing time. The fast multipole method are widely used for the acceleration of BEM, however, its dependency of kernels and order of elements caused difficulties on the implementation for engineering applications. Since the H-matrices techniques are robust and easy to implement, the adaptive cross approximation is adapted to overcome the well-known drawback of fully populated acoustical system matrices in boundary element method. Since decreases of convergence rate when frequency raises are observed in former researches on the iterative solvers for underwater vibro-acoustical problems, engineering application of FE-BE method is restricted by the absence of robustness in fast iterative solvers. Using the traditional directly coupled scheme, a new preconditioner is developed in this paper. With a group of iterative solvers implemented, the efficiency with respect to their memory consumption and computation time is compared for a simple model and a more complex structure problem. As indicated by the results, the solver developed in this paper has better stability in convergence rate than traditional iterative solvers when the frequency rises.
{"title":"An iterative solver for FE-BE coupling in large-scale fluid-structure interaction","authors":"Jinshi Liu, S. Chao","doi":"10.1109/COA.2016.7535663","DOIUrl":"https://doi.org/10.1109/COA.2016.7535663","url":null,"abstract":"For solving the prediction problem of sound radiation from structures, both the structural and acoustical regions have to be researched. Fluid-structure interaction incorporates the mutual influence of acoustical medium and structure. This interaction occurs at the coupling interface between the two adjacent domains. In case of thin structures and dense fluids, a strong coupling scheme between the two problems is essential, since the feedback of the acoustic pressure onto the structure is not negligible. In this paper, the structural part is modeled with the finite element (FE) method. An interface to the commercial finite element package ANSYS is set up to import the structural matrices of stiffness and mess. The exterior acoustic problem is efficiently modeled with the boundary element method, and the CHIEF method with internal nodes generated randomly is adopted to avoid non-uniqueness of solution. Classical BEM formulations suffer from fully populated matrices, leading to a restriction in both memory consumption and computing time. The fast multipole method are widely used for the acceleration of BEM, however, its dependency of kernels and order of elements caused difficulties on the implementation for engineering applications. Since the H-matrices techniques are robust and easy to implement, the adaptive cross approximation is adapted to overcome the well-known drawback of fully populated acoustical system matrices in boundary element method. Since decreases of convergence rate when frequency raises are observed in former researches on the iterative solvers for underwater vibro-acoustical problems, engineering application of FE-BE method is restricted by the absence of robustness in fast iterative solvers. Using the traditional directly coupled scheme, a new preconditioner is developed in this paper. With a group of iterative solvers implemented, the efficiency with respect to their memory consumption and computation time is compared for a simple model and a more complex structure problem. As indicated by the results, the solver developed in this paper has better stability in convergence rate than traditional iterative solvers when the frequency rises.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114938320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535711
Ana Bela dos Santos, P. Felisberto, S. Jesus
This work addresses the usage of ship radiated noise to estimate the ocean acoustic water propagation channel response between two vertical line arrays. We derive an expression for the frequency response channel estimate using a normal mode development based on cross-correlation methods, in a similar way as Roux et al. [1]. Its applicability and limitations in simulated and real conditions is discussed. Simulations are conducted using the normal mode model KRAKEN, based on the experimental setup and environmental parameters gathered during the RADAR'07 sea trial, off the west coast of Portugal, in July of 2007. In this sea trial two drifting vertical line arrays with 16 and 8 hydrophones were deployed in a range independent bathymetric area, at 300 m and 1.3 km distance from the Research Vessel NRP D. Carlos I, whose track then moved away from the arrays, radiating noise in the frequency band bellow 750 Hz. The wave fronts structure, obtained from actual acoustic data of the above referred sea trial, reveals agreement with the simulations obtained with the proposed approach. These results suggest the feasibility of the method for future application in a passive ocean acoustics tomography framework to the estimation of sound speed perturbations in the water column.
本文研究了利用船舶辐射噪声来估计两个垂直线阵列之间的海洋水声传播通道响应。我们采用与Roux等人[1]类似的方式，使用基于互相关方法的正态模式开发，推导出频率响应信道估计的表达式。讨论了其在模拟和实际条件下的适用性和局限性。基于2007年7月在葡萄牙西海岸进行的RADAR’07海上试验中收集的实验设置和环境参数，使用正常模式模型KRAKEN进行了模拟。在这次海上试验中，在距离研究船NRP D. Carlos I号300米和1.3公里的距离上，两个漂流垂直线阵列分别部署了16个和8个水听器，然后该船的轨迹远离阵列，辐射750 Hz以下频段的噪声。从上述海试的实际声学数据中得到的波前结构与用该方法模拟得到的结果一致。这些结果表明，该方法在未来的被动海洋声学层析框架中应用于估计水柱中的声速扰动是可行的。
{"title":"Acoustic channel frequency response estimation using sources of opportunity","authors":"Ana Bela dos Santos, P. Felisberto, S. Jesus","doi":"10.1109/COA.2016.7535711","DOIUrl":"https://doi.org/10.1109/COA.2016.7535711","url":null,"abstract":"This work addresses the usage of ship radiated noise to estimate the ocean acoustic water propagation channel response between two vertical line arrays. We derive an expression for the frequency response channel estimate using a normal mode development based on cross-correlation methods, in a similar way as Roux et al. [1]. Its applicability and limitations in simulated and real conditions is discussed. Simulations are conducted using the normal mode model KRAKEN, based on the experimental setup and environmental parameters gathered during the RADAR'07 sea trial, off the west coast of Portugal, in July of 2007. In this sea trial two drifting vertical line arrays with 16 and 8 hydrophones were deployed in a range independent bathymetric area, at 300 m and 1.3 km distance from the Research Vessel NRP D. Carlos I, whose track then moved away from the arrays, radiating noise in the frequency band bellow 750 Hz. The wave fronts structure, obtained from actual acoustic data of the above referred sea trial, reveals agreement with the simulations obtained with the proposed approach. These results suggest the feasibility of the method for future application in a passive ocean acoustics tomography framework to the estimation of sound speed perturbations in the water column.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124770348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Terrain matching navigation provides a capability for estimating position by matching real-time measurement of terrain to a terrain database. Since this process is without errors accumulating with time, it is very attractive as compared to limit the drift errors inherent in dead-reckoning or inertial navigation for underwater vehicles. The geometric description of an undulating terrain surface as a mathematical function or look-up table is generally nonlinear, which leads to a nonlinear state estimation problem. However, the maximum likelihood estimation algorithm uses probability criterion directly and has a theoretical advantage in solving nonlinear state estimation problems. The detail of terrain matching aided navigation based on maximum likelihood estimation is presented in this paper. In the method, a multi-beam echo sounder is used to acquire bathymetry data, and a maximum likelihood estimation algorithm is used for matching the analysis between real-time bathymetry and the reference digital map. Terrain statistical information is also introduced in order to select the most suitable terrain matching field. The results of simulation demonstrate that the proposed approach is feasible, accurate, and robust.
{"title":"Terrain aided navigation for underwater vehicles using maximum likelihood method","authors":"Dongdong Peng, Zhou Tian, Haisen Li, Wanyuan Zhang","doi":"10.1109/COA.2016.7535750","DOIUrl":"https://doi.org/10.1109/COA.2016.7535750","url":null,"abstract":"Terrain matching navigation provides a capability for estimating position by matching real-time measurement of terrain to a terrain database. Since this process is without errors accumulating with time, it is very attractive as compared to limit the drift errors inherent in dead-reckoning or inertial navigation for underwater vehicles. The geometric description of an undulating terrain surface as a mathematical function or look-up table is generally nonlinear, which leads to a nonlinear state estimation problem. However, the maximum likelihood estimation algorithm uses probability criterion directly and has a theoretical advantage in solving nonlinear state estimation problems. The detail of terrain matching aided navigation based on maximum likelihood estimation is presented in this paper. In the method, a multi-beam echo sounder is used to acquire bathymetry data, and a maximum likelihood estimation algorithm is used for matching the analysis between real-time bathymetry and the reference digital map. Terrain statistical information is also introduced in order to select the most suitable terrain matching field. The results of simulation demonstrate that the proposed approach is feasible, accurate, and robust.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129657859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535640
Zhen Qi, Qing-yu Liu
A simultaneous data acquisition and analysis method for the array's internal self-noise and its external monitoring noise are presented in this paper to accurately evaluate the effect of platform self-noise on sonar detection. A sea trial is conducted in a certain sea area of China, in which the self-noise for a typical cruise speed and depth is acquired. The sea trial data are analyzed by using single channel, multi-channel and comparison analysis methods. These measuring results could provide the characteristics of the sonar platform self-noise varyiations with the working conditions, the space distribution features of the array's self-noise, and the relationship between the array's internal self-noise and its external monitoring noise.
{"title":"Study on data acquisition and analysis method for sonar platform self-noise","authors":"Zhen Qi, Qing-yu Liu","doi":"10.1109/COA.2016.7535640","DOIUrl":"https://doi.org/10.1109/COA.2016.7535640","url":null,"abstract":"A simultaneous data acquisition and analysis method for the array's internal self-noise and its external monitoring noise are presented in this paper to accurately evaluate the effect of platform self-noise on sonar detection. A sea trial is conducted in a certain sea area of China, in which the self-noise for a typical cruise speed and depth is acquired. The sea trial data are analyzed by using single channel, multi-channel and comparison analysis methods. These measuring results could provide the characteristics of the sonar platform self-noise varyiations with the working conditions, the space distribution features of the array's self-noise, and the relationship between the array's internal self-noise and its external monitoring noise.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130203400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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